Demon rune

The demon rune is an item in Doom (2016) which occurs only during multiplayer and SnapMap game play. It appears as a floating red pentagram with a number of set spawn points in the level, which appear as small patches of smouldering lava. It transforms a player into one of several powerful demons when touched.

Tactical details
When taken, the player who obtains the demon rune will be transformed into a demon they selected before the match. In multiplayer, with the exception of Soul Harvest mode, this transformation lasts for a total of 60 seconds, after which the player will revert to his or her human form if they have survived. Although each demon is powerful in its own right, it is possible for enemy players to kill the player who has become the demon, and doing so will cause the demon rune to drop, where it can be collected by any other player to transform and lay waste to his or her enemies.

The demon rune will otherwise eventually respawn, with its reappearance announced verbally to all players in the game 15 seconds beforehand with the message, "Incoming demon rune."

In Soul Harvest, the demon rune is a central feature of the game mode and the transformation time is unlimited - a player must be killed in order to drop the rune. When they are killed, the rune will drop, allowing another player to become the demon, and transferring the souls the demon had captured to their killer.

The Gauss cannon, chainsaw, and the BFG are powerful counters to the demon rune. All of these power weapons can usually obliterate a transformed player entirely.

In SnapMap, the demon rune has no time limit, and the player will not transform back into a human unless they are either killed or are affected by a trigger in the map which changes the player race value back to human. Respawning behavior, if any, is under the control of the map author.

Demons
The demons currently available for use, in order of unlocking for the base game, are listed below. One demon was added in each of the three packs for the game, but these are now unlockable by all players since the v6.66 update.

Note that as of v6.66, only the revenant, baron of Hell, and mancubus are available in SnapMap. The demon type used by a player is under the control of the SnapMap's author in that mode.